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1.
Cancer ; 130(18): 3090-3105, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-39012928

RESUMEN

Neuroendocrine neoplasms are a diverse group of neoplasms that can occur in various areas throughout the body. Well-differentiated neuroendocrine tumors (NETs) most often arise in the gastrointestinal tract, termed gastroenteropancreatic neuroendocrine tumors (GEP-NETs). Although GEP-NETs are still uncommon, their incidence and prevalence have been steadily increasing over the past decades. The primary treatment for GEP-NETs is surgery, which offers the best chance for a cure. However, because GEP-NETs are often slow-growing and do not cause symptoms until they have spread widely, curative surgery is not always an option. Significant advances have been made in systemic and locoregional treatment options in recent years, including peptide-receptor radionuclide therapy with α and ß emitters, somatostatin analogs, chemotherapy, and targeted molecular therapies.


Asunto(s)
Neoplasias Intestinales , Tumores Neuroendocrinos , Neoplasias Pancreáticas , Neoplasias Gástricas , Humanos , Tumores Neuroendocrinos/terapia , Tumores Neuroendocrinos/patología , Neoplasias Pancreáticas/terapia , Neoplasias Pancreáticas/patología , Neoplasias Gástricas/terapia , Neoplasias Gástricas/patología , Neoplasias Intestinales/terapia , Neoplasias Intestinales/patología , Somatostatina/análogos & derivados , Somatostatina/uso terapéutico , Terapia Molecular Dirigida/métodos
2.
Radiographics ; 44(1): e230097, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-38060426

RESUMEN

Radiopharmaceutical therapies (RPTs) are gaining increased interest with the recent emergence of novel safe and effective theranostic agents, improving outcomes for thousands of patients. The term theranostics refers to the use of diagnostic and therapeutic agents that share the same molecular target; a major step toward precision medicine, especially for oncologic applications. The authors dissect the fundamentals of theranostics in nuclear medicine. First, they explain the radioactive decay schemes and the characteristics of emitted electromagnetic radiation used for imaging, as well as particles used for therapeutic purposes, followed by the interaction of the different types of radiation with tissue. These concepts directly apply to clinical RPTs and play a major role in the efficacy and toxicity profile of different radiopharmaceutical agents. Personalized dosimetry is a powerful tool that can help estimate patient-specific absorbed doses, in tumors as well as normal organs. Dosimetry in RPT is an area of active investigation, as most of what we know about the relationship between delivered dose and tissue damage is extrapolated from external-beam radiation therapy; more research is needed to understand this relationship as it pertains to RPTs. Tumor heterogeneity is increasingly recognized as an important prognostic factor. Novel molecular imaging agents, often in combination with fluorine 18-fluorodeoxyglucose, are crucial for assessment of target expression in the tumor and potential hypermetabolic disease that may lack the molecular target expression. ©RSNA, 2023 Test Your Knowledge questions are available in the supplemental material.


Asunto(s)
Neoplasias , Médicos , Humanos , Medicina de Precisión/métodos , Radiofármacos/uso terapéutico , Neoplasias/diagnóstico por imagen , Neoplasias/radioterapia , Imagen Molecular
3.
Cancers (Basel) ; 15(11)2023 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-37296836

RESUMEN

Adrenocortical cancer is an aggressive endocrine malignancy with an incidence of 0.72 to 1.02 per million people/year, and a very poor prognosis with a five-year survival rate of 22%. As an orphan disease, clinical data are scarce, meaning that drug development and mechanistic research depend especially on preclinical models. While a single human ACC cell line was available for the last three decades, over the last five years, many new in vitro and in vivo preclinical models have been generated. Herein, we review both in vitro (cell lines, spheroids, and organoids) and in vivo (xenograft and genetically engineered mouse) models. Striking leaps have been made in terms of the preclinical models of ACC, and there are now several modern models available publicly and in repositories for research in this area.

4.
Wellcome Open Res ; 7: 148, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36324702

RESUMEN

Background: Streptococcus agalactiae is a normal commensal of the human gastro-intestinal and female genital tracts. It causes serious disease in neonates and pregnant women, as well as non-pregnant adults. Food-borne outbreaks have also been described. A link between invasive Group B streptococcus (GBS) infection in humans caused by S. agalactiae serotype III-4, sequence type 283 (ST283) and the consumption of raw fresh-water fish was first described in Singapore in 2015. Case presentation: We report the simultaneous occurrence of acute fever and myalgia in two sisters who were visiting Laos. Both were found to have invasive GBS ST283 infection, confirmed by blood culture. Infection was temporally linked to fish consumption. They responded well to intravenous antibiotics within 48 hours. Conclusions: Food-borne transmission of Streptococcus agalactiae is an important and under-recognised source of serious human disease throughout Southeast Asia and possibly beyond.

5.
Cancers (Basel) ; 14(22)2022 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-36428741

RESUMEN

Neuroendocrine neoplasia (NENs) are a complex and heterogeneous group of cancers that can arise from neuroendocrine tissues throughout the body and differentiate them from other tumors. Their low incidence and high diversity make many of them orphan conditions characterized by a low incidence and few dedicated clinical trials. Study of the molecular and genetic nature of these diseases is limited in comparison to more common cancers and more dependent on preclinical models, including both in vitro models (such as cell lines and 3D models) and in vivo models (such as patient derived xenografts (PDXs) and genetically-engineered mouse models (GEMMs)). While preclinical models do not fully recapitulate the nature of these cancers in patients, they are useful tools in investigation of the basic biology and early-stage investigation for evaluation of treatments for these cancers. We review available preclinical models for each type of NEN and discuss their history as well as their current use and translation.

6.
Int J Mol Sci ; 23(20)2022 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-36293452

RESUMEN

Computational modeling can provide a mechanistic and quantitative framework for describing intracellular spatial heterogeneity of solutes such as oxygen partial pressure (pO2). This study develops and evaluates a finite-element model of oxygen-consuming mitochondrial bioenergetics using the COMSOL Multiphysics program. The model derives steady-state oxygen (O2) distributions from Fickian diffusion and Michaelis-Menten consumption kinetics in the mitochondria and cytoplasm. Intrinsic model parameters such as diffusivity and maximum consumption rate were estimated from previously published values for isolated and intact mitochondria. The model was compared with experimental data collected for the intracellular and mitochondrial pO2 levels in human cervical cancer cells (HeLa) in different respiratory states and under different levels of imposed pO2. Experimental pO2 gradients were measured using lifetime imaging of a Förster resonance energy transfer (FRET)-based O2 sensor, Myoglobin-mCherry, which offers in situ real-time and noninvasive measurements of subcellular pO2 in living cells. On the basis of these results, the model qualitatively predicted (1) the integrated experimental data from mitochondria under diverse experimental conditions, and (2) the impact of changes in one or more mitochondrial processes on overall bioenergetics.


Asunto(s)
Consumo de Oxígeno , Oxígeno , Humanos , Mioglobina/metabolismo , Simulación por Computador , Metabolismo Energético
7.
Vaccine ; 40(42): 6163-6178, 2022 10 06.
Artículo en Inglés | MEDLINE | ID: mdl-36153153

RESUMEN

We undertook a Phase 4 clinical trial to assess the effect of time interval between booster doses on serological responses to AVP. The primary objective was to evaluate responses to a single booster dose in two groups of healthy adults who had previously received a complete 4-dose primary course. Group A had received doses on schedule while Group B had not had one for ≥2 years. Secondary objectives were to evaluate the safety and tolerability of AVP booster doses, and to gain information on correlates of protection to aid future anthrax vaccine development. Blood samples were taken on Day 1 before dosing, and on Days 8, 15, 29 and 120, to measure Toxin Neutralisation Assay (TNA) NF50 values and concentrations of IgG antibodies against Protective Antigen (PA), Lethal Factor (LF) and Edema Factor (EF) by ELISA. For each serological parameter, fold changes from baseline following the trial AVP dose were greater in Group B than Group A at every time-point studied. Peak responses correlated positively with time since last AVP dose (highest values being observed after intervals of ≥10 years), and negatively with number of previous doses (highest values occurring in individuals who had received a primary course only). In 2017, having reviewed these results, the Joint Committee on Vaccination and Immunisation (JCVI) updated UK anthrax vaccination guidelines, extending the interval between routine AVP boosters from one to 10 years. Booster doses of AVP induce significant IgG responses against the three anthrax toxin components, particularly PA and LF. Similarly high responses were observed in TNA, a recognised surrogate for anthrax vaccine efficacy. Analysis of the 596 TNA results showed that anti-PA and anti-LF IgG make substantial independent contributions to neutralisation of anthrax lethal toxin. AVP may therefore have advantages over anthrax vaccines that depend on generating immunity to PA alone.


Asunto(s)
Vacunas contra el Carbunco , Carbunco , Bacillus anthracis , Adulto , Carbunco/prevención & control , Anticuerpos Antibacterianos , Antígenos Bacterianos , Humanos , Inmunoglobulina G , Vacunación/métodos
8.
Int J Antimicrob Agents ; 60(4): 106659, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35988665

RESUMEN

INTRODUCTION: Bloodstream infections (BSIs) are a leading cause of sepsis, which is a life-threatening condition that significantly contributes to the mortality of bacterial infections. Aminoglycoside antibiotics such as gentamicin or amikacin are essential medicines in the treatment of BSIs, but their clinical efficacy is increasingly being compromised by antimicrobial resistance. The aminoglycoside apramycin has demonstrated preclinical efficacy against aminoglycoside-resistant and multidrug-resistant (MDR) Gram-negative bacilli (GNB) and is currently in clinical development for the treatment of critical systemic infections. METHODS: This study collected a panel of 470 MDR GNB isolates from healthcare facilities in Cambodia, Laos, Singapore, Thailand and Vietnam for a multicentre assessment of their antimicrobial susceptibility to apramycin in comparison with other aminoglycosides and colistin by broth microdilution assays. RESULTS: Apramycin and amikacin MICs ≤ 16 µg/mL were found for 462 (98.3%) and 408 (86.8%) GNB isolates, respectively. Susceptibility to gentamicin and tobramycin (MIC ≤ 4 µg/mL) was significantly lower at 122 (26.0%) and 101 (21.5%) susceptible isolates, respectively. Of note, all carbapenem and third-generation cephalosporin-resistant Enterobacterales, all Acinetobacter baumannii and all Pseudomonas aeruginosa isolates tested in this study appeared to be susceptible to apramycin. Of the 65 colistin-resistant isolates tested, four (6.2%) had an apramycin MIC > 16 µg/mL. CONCLUSION: Apramycin demonstrated best-in-class activity against a panel of GNB isolates with resistances to other aminoglycosides, carbapenems, third-generation cephalosporins and colistin, warranting continued consideration of apramycin as a drug candidate for the treatment of MDR BSIs.


Asunto(s)
Amicacina , Colistina , Aminoglicósidos , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Asia Sudoriental , Cultivo de Sangre , Carbapenémicos , Cefalosporinas , Colistina/farmacología , Farmacorresistencia Bacteriana Múltiple , Gentamicinas , Bacterias Gramnegativas , Pruebas de Sensibilidad Microbiana , Nebramicina/análogos & derivados , Pseudomonas aeruginosa , Tobramicina
9.
Sci Rep ; 12(1): 8674, 2022 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-35606475

RESUMEN

The environmental distribution of Burkholderia pseudomallei, the causative agent of melioidosis, remains poorly understood. B. pseudomallei is known to have the ability to occupy a variety of environmental niches, particularly in soil. This paper provides novel information about a putative association of soil biogeochemical heterogeneity and the vertical distribution of B. pseudomallei. We investigated (1) the distribution of B. pseudomallei along a 300-cm deep soil profile together with the variation of a range of soil physico-chemical properties; (2) whether correlations between the distribution of B. pseudomallei and soil physico-chemical properties exist and (3) when they exist, what such correlations indicate with regards to the environmental conditions conducive to the occurrence of B. pseudomallei in soils. Unexpectedly, the highest concentrations of B. pseudomallei were observed between 100 and 200 cm below the soil surface. Our results indicate that unravelling the environmental conditions favorable to B. pseudomallei entails considering many aspects of the actual complexity of soil. Important recommendations regarding environmental sampling for B. pseudomallei can be drawn from this work, in particular that collecting samples down to the water table is of foremost importance, as groundwater persistence appears to be a controlling factor of the occurrence of B. pseudomallei in soil.


Asunto(s)
Burkholderia pseudomallei , Melioidosis , Humanos , Melioidosis/epidemiología , Suelo , Microbiología del Suelo , Manejo de Especímenes
10.
Clin Psychol Rev ; 93: 102132, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35316672

RESUMEN

Therapist drift refers to the tendency for psychologists to move away from the delivery of the evidence-based practices in which they are trained, even when resourced to implement them. When therapists do not provide, or only partially provide, empirically supported treatments their patients may receive interventions that are not effective, or that are harmful. The aim of the current study was to conduct a systematic review of the literature to ascertain the correlates of therapist drift in psychological practice, focusing on therapist characteristics. Relevant articles were identified through a comprehensive search of the literature. Sixty-six studies met the inclusion criteria and nine therapist characteristics that correlate with therapist drift were identified. These characteristics included: (1) therapist knowledge; (2) attitudes toward research; (3) therapist anxiety; (4) clinical experience; (5) therapist age; (6) theoretical orientation; (7) critical thinking; (8) personality traits; and (9) cultural competency. The interrelationships between these factors are explored and the clinical implications of results are discussed. Recommendations are made for future research.


Asunto(s)
Trastornos de Ansiedad , Práctica Psicológica , Trastornos de Ansiedad/terapia , Práctica Clínica Basada en la Evidencia , Humanos
11.
JAC Antimicrob Resist ; 4(1): dlac006, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35146428

RESUMEN

BACKGROUND: There is a need for simple microbiology diagnostics to enable antimicrobial resistance surveillance in low- and middle-income countries. OBJECTIVES: To investigate the field utility of InTray COLOREX plates for urine culture and ESBL detection. METHODS: Clinical urine samples from Mahosot Hospital, Vientiane, Lao PDR were inoculated onto chromogenic media and InTray COLOREX Screen plates between June and August 2020. Urine and isolates from other clinical specimens were inoculated onto COLOREX ESBL plates. A simulated field study investigating the field utility of the InTray COLOREX plates was also completed. RESULTS: In total, 355 urine samples were inoculated onto standard chromogenic agar and InTray COLOREX Screen plates, and 154 urine samples and 54 isolates from other clinical specimens on the COLOREX ESBL plates. Growth was similar for the two methods (COLOREX Screen 41%, standard method 38%) with 20% discordant results, mainly due to differences in colony counts or colonial appearance. Contamination occurred in 13% of samples, with the COLOREX Screen plates showing increased contamination rates, potentially due to condensation. ESBL producers were confirmed from 80% of isolates from the COLOREX ESBL plates, and direct plating provided rapid detection of presumptive ESBL producers. Burkholderia pseudomallei also grew well on the ESBL plates, a relevant finding in this melioidosis-endemic area. CONCLUSIONS: The InTray COLOREX Screen and ESBL plates were simple to use and interpret, permitting rapid detection of uropathogens and ESBLs, and have the potential for easy transport and storage from field sites and use in laboratories with low capacity.

12.
BMC Microbiol ; 21(1): 213, 2021 07 16.
Artículo en Inglés | MEDLINE | ID: mdl-34266382

RESUMEN

BACKGROUND: Burkholderia pseudomallei is the bacterial causative agent of melioidosis, a difficult disease to diagnose clinically with high mortality if not appropriately treated. Definitive diagnosis requires isolation and identification of the organism. With the increased adoption of MALDI-TOF MS for the identification of bacteria, we established a method for rapid identification of B. pseudomallei using the Vitek MS, a system that does not currently have B. pseudomallei in its in-vitro diagnostic database. RESULTS: A routine direct spotting method was employed to create spectra and SuperSpectra. An initial B. pseudomallei SuperSpectrum was created at Shoklo Malaria Research Unit (SMRU) from 17 reference isolates (46 spectra). When tested, this initial SMRU SuperSpectrum was able to identify 98.2 % (54/55) of Asian isolates, but just 46.7 % (35/75) of Australian isolates. Using spectra (430) from different reference and clinical isolates, two additional SMRU SuperSpectra were created. Using the combination of all SMRU SuperSpectra with seven existing SuperSpectra from Townsville, Australia 119 (100 %) Asian isolates and 31 (100 %) Australian isolates were correctly identified. In addition, no misidentifications were obtained when using these 11 SuperSpectra when tested with 34 isolates of other bacteria including the closely related species Burkholderia thailandensis and Burkholderia cepacia. CONCLUSIONS: This study has established a method for identification of B. pseudomallei using Vitek MS, and highlights the impact of geographical differences between strains for identification using this technique.


Asunto(s)
Burkholderia pseudomallei/química , Burkholderia pseudomallei/aislamiento & purificación , Melioidosis/diagnóstico , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Técnicas Bacteriológicas/instrumentación , Técnicas Bacteriológicas/normas , Melioidosis/microbiología , Reproducibilidad de los Resultados , Especificidad de la Especie
13.
Am J Trop Med Hyg ; 104(4): 1582-1585, 2021 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-33646978

RESUMEN

Bloodstream infections cause substantial morbidity and mortality. However, despite clinical suspicion of such infections, blood cultures are often negative. We investigated blood cultures that were negative after 5 days of incubation for the presence of bacterial pathogens using specific (Rickettsia spp. and Leptospira spp.) and a broad-range 16S rRNA PCR. From 190 samples, 53 (27.9%) were positive for bacterial DNA. There was also a high background incidence of dengue (90/112 patient serum positive, 80.4%). Twelve samples (6.3%) were positive for Rickettsia spp., including two Rickettsia typhi. The 16S rRNA PCR gave 41 positives; Escherichia coli and Klebsiella pneumoniae were identified in 11 and eight samples, respectively, and one Leptospira species was detected. Molecular investigation of negative blood cultures can identify potential pathogens that will otherwise be missed by routine culture. Patient management would have been influenced in all 53 patients for whom a bacterial organism was identified, and 2.3-6.1% of patients would likely have had an altered final outcome. These findings warrant further study, particularly to determine the cost-benefit for routine use, ways of implementation, and timing of PCR for organisms such as Rickettsia and Leptospira, which are important pathogens in rural Asia.


Asunto(s)
Cultivo de Sangre/estadística & datos numéricos , ADN Bacteriano/análisis , ADN Bacteriano/genética , Escherichia coli/genética , Escherichia coli/patogenicidad , Humanos , Laos/epidemiología , Leptospira/genética , Leptospira/patogenicidad , Patología Molecular , Reacción en Cadena de la Polimerasa , ARN Ribosómico 16S/genética , Rickettsia/genética , Rickettsia/patogenicidad , Rickettsia typhi/genética , Rickettsia typhi/patogenicidad
14.
Valasan Kanphaet Lao ; 12: 67-70, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37868344

RESUMEN

Background: Global guidelines from the World Health Organization on discharging patients diagnosed with COVID-19 changed in 2021 to a symptom-based rather than negative PCR-based approach. Studies have shown that shedding of viable virus continues for approximately eight days after symptom onset in most patients. In Vientiane, Laos, until now, patients diagnosed with asymptomatic or mild COVID-19 are hospitalised for 2 weeks and then, if they still test PCR positive for SARS-CoV-2, stay for a further week in a designated quarantine hotel before being discharged home. Objective: The aim of this pilot study was to investigate the risk of transmission of SARS-CoV-2 to household contacts of discharged patients who are still PCR-positive following 2-3 weeks quarantine in Vientiane, Lao PDR. Methods: Adult participants, who were resident in Vientiane Capital and who were about to be discharged from hospital (after 2 weeks hospitalisation), or from a quarantine hotel, following a further one-week quarantine, were screened to assess eligibility for the study. The household of each case was visited a maximum of 48 hours before or up to 24 hours after the participant was discharged and a nasopharyngeal swab was taken from all household members. Repeat nasopharyngeal swabs from cases and contacts were taken on day 7 and day 14 after discharge home of each case. Results: Between 20th May 2021 and 27th August 2021, 55 cases and 84 contacts in 27 households were enrolled in the study. The median [range] age of all 139 included participants was 26.5 years [3 months to 83 years] and 83 (60%) were female. By household, the median [range] number of cases and contacts were 1 [1-6] and 3 [1-13] respectively. At discharge home 32/48 (67%) cases tested positive for SARS-CoV-2. By day 7 11 of 47 cases (23%) still tested positive for SARS-CoV-2 by PCR and by day 14 this number was 2/24 (8%). No contacts tested positive during follow up and the numbers tested at the time of discharge of the case, 7 days later and 2 weeks later were 56, 57 and 37 respectively. Loss to follow up at day 7 and day 14 ranged from 15-50% (participants not at home at the time of visits). Conclusion: In this pilot study we found no evidence of onward transmission of SARS-CoV-2 to contacts of cases discharged home with a positive PCR result. This suggests the current discharge policy for mild to moderate COVID-19 case following 2 weeks in hospital in the Lao PDR is safe.

15.
Cancer Gene Ther ; 28(1-2): 98-111, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-32632271

RESUMEN

Adoptive cell therapy (ACT) using tumor-specific tumor-infiltrating lymphocytes (TILs) has demonstrated success in patients where tumor-antigen specific TILs can be harvested from the tumor, expanded, and re-infused in combination with a preparatory regimen and IL2. One major issue for non-immunogenic tumors has been that the isolated TILs lack tumor specificity and thus possess limited in vivo therapeutic function. An oncolytic virus (OV) mediates an immunogenic cell death for cancer cells, leading to elicitation and dramatic enhancement of tumor-specific TILs. We hypothesized that the tumor-specific TILs elicited and promoted by an OV would be a great source for ACT for solid cancer. In this study, we show that a local injection of oncolytic poxvirus in MC38 tumor with low immunogenicity in C57BL/6 mice, led to elicitation and accumulation of tumor-specific TILs in the tumor tissue. Our analyses indicated that IL2-armed OV-elicited TILs contain lower quantities of exhausted PD-1hiTim-3+ CD8+ T cells and regulatory T cells. The isolated TILs from IL2-expressing OV-treated tumor tissue retained high tumor specificity after expansion ex vivo. These TILs resulted in significant tumor regression and improved survival after adoptive transfer in mice with established MC38 tumor. Our study showcases the feasibility of using an OV to induce tumor-reactive TILs that can be expanded for ACT.


Asunto(s)
Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Inmunoterapia Adoptiva/métodos , Linfocitos Infiltrantes de Tumor/inmunología , Virus Oncolíticos/inmunología , Animales , Femenino , Humanos , Ratones
16.
Lancet Infect Dis ; 20(12): e307-e311, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32853549

RESUMEN

Improving evidence for action is crucial to tackle antimicrobial resistance. The number of interventions for antimicrobial resistance is increasing but current research has major limitations in terms of efforts, methods, scope, quality, and reporting. Moving the agenda forwards requires an improved understanding of the diversity of interventions, their feasibility and cost-benefit, the implementation factors that shape and underpin their effectiveness, and the ways in which individual interventions might interact synergistically or antagonistically to influence actions against antimicrobial resistance in different contexts. Within the efforts to strengthen the global governance of antimicrobial resistance, we advocate for the creation of an international One Health platform for online learning. The platform will synthesise the evidence for actions on antimicrobial resistance into a fully accessible database; generate new scientific insights into the design, implementation, evaluation, and reporting of the broad range of interventions relevant to addressing antimicrobial resistance; and ultimately contribute to the goal of building societal resilience to this central challenge of the 21st century.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana , Salud Única , Animales , Humanos
17.
J Vis Exp ; (159)2020 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-32449724

RESUMEN

Custom designed endonucleases, such as RNA-guided Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9, enable efficient genome editing in mammalian cells. Here we describe detailed procedures to seamlessly genome edit the hepatocyte nuclear factor 4 alpha (HNF4α) locus as an example in human pluripotent stem cells. Combining a piggyBac-based donor plasmid and the CRISPR-Cas9 nickase mutant in a two-step genetic selection, we demonstrate correct and efficient targeting of the HNF4α locus.


Asunto(s)
Edición Génica/métodos , Células Madre Pluripotentes/metabolismo , Mutación Puntual/genética , Secuencia de Bases , Sistemas CRISPR-Cas/genética , Elementos Transponibles de ADN/genética , Vectores Genéticos/genética , Genoma Humano , Humanos
18.
Am J Trop Med Hyg ; 102(5): 1137-1143, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32157990

RESUMEN

Although there has been an increasing incidence of bacteremia caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae (ESBL-E) across South East Asia, there are sparse data from the Lao PDR, where laboratory capacity for antimicrobial resistance surveillance is limited. We, therefore, retrospectively reviewed bacteremia caused by ESBL-producing Escherichia coli and Klebsiella pneumoniae between 2010 and 2014 at Mahosot Hospital, Vientiane, Lao PDR. Clinical and laboratory data relating to all episodes of ESBL-E bacteremia were reviewed over the 5-year period and compared with non-ESBL-E bacteremia. Blood cultures positive for E. coli or K. pneumoniae were identified retrospectively from laboratory records. Clinical and laboratory data were extracted from research databases and case notes and analyzed using STATA. Between 2010 and 2014, we identified 360 patients with E. coli (n = 249) or K. pneumoniae (n = 111) bacteremia, representing 34.8% of all patients with clinically significant bacteremia. Seventy-two (20%) isolates produced ESBL; E. coli accounted for 15.3% (55/360) and K. pneumoniae for 4.7% (17/360), respectively. The incidence of ESBL-producing E. coli bacteremia rose during the study period. By multiple logistic analysis, reported antibiotic use in the previous week was significantly associated with ESBL positivity (P < 0.001, odds ratio 3.89). Although multiresistant, most ESBL-producing E. coli and K. pneumoniae remained susceptible to meropenem (65/65; 100%) and amikacin (64/65; 98.5%). We demonstrated an alarming increase in the incidence of ESBL-E as a cause of bacteremia in Vientiane during the study period. This has implications for empiric therapy of sepsis in Laos, and ongoing surveillance is essential.


Asunto(s)
Bacteriemia/microbiología , Infecciones por Escherichia coli/tratamiento farmacológico , Escherichia coli/efectos de los fármacos , Infecciones por Klebsiella/tratamiento farmacológico , beta-Lactamasas/metabolismo , Adolescente , Adulto , Anciano , Antibacterianos/uso terapéutico , Bacteriemia/tratamiento farmacológico , Bacteriemia/epidemiología , Escherichia coli/enzimología , Infecciones por Escherichia coli/epidemiología , Femenino , Humanos , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/efectos de los fármacos , Klebsiella pneumoniae/enzimología , Laos/epidemiología , Masculino , Pruebas de Sensibilidad Microbiana , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Adulto Joven , Resistencia betalactámica
19.
iScience ; 16: 206-217, 2019 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-31185456

RESUMEN

During mammalian development, liver differentiation is driven by signals that converge on multiple transcription factor networks. The hepatocyte nuclear factor signaling network is known to be essential for hepatocyte specification and maintenance. In this study, we have generated deletion and point mutants of hepatocyte nuclear factor-4alpha (HNF4α) to precisely evaluate the function of protein domains during hepatocyte specification from human pluripotent stem cells. We demonstrate that nuclear HNF4α is essential for hepatic progenitor specification, and the introduction of point mutations in HNF4α's Small Ubiquitin-like Modifier (SUMO) consensus motif leads to disrupted hepatocyte differentiation. Taking a multiomics approach, we identified key deficiencies in cell biology, which included dysfunctional metabolism, substrate adhesion, tricarboxylic acid cycle flux, microRNA transport, and mRNA processing. In summary, the combination of genome editing and multiomics analyses has provided valuable insight into the diverse functions of HNF4α during pluripotent stem cell entry into the hepatic lineage and during hepatocellular differentiation.

20.
PLoS One ; 14(3): e0212113, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30845203

RESUMEN

BACKGROUND: Without an effective vaccine, as was the case early in the 2014-2016 Ebola Outbreak in West Africa, disease control depends entirely on interrupting transmission through early disease detection and prompt patient isolation. Lateral Flow Immunoassays (LFI) are a potential supplement to centralized reference laboratory testing for the early diagnosis of Ebola Virus Disease (EVD). The goal of this study was to assess the performance of commercially available simple and rapid antigen detection LFIs, submitted for review to the WHO via the Emergency Use Assessment and Listing procedure. The study was performed in an Ebola Treatment Centre laboratory involved in EVD testing in Sierra Leone. In light of the current Ebola outbreak in May 2018 in the Democratic Republic of Congo, which highlights the lack of clarity in the global health community about appropriate Ebola diagnostics, our findings are increasingly critical. METHODS: A cross-sectional study was conducted to assess comparative performance of four LFIs for detecting EVD. LFIs were assessed against the same 328 plasma samples and 100 whole EDTA blood samples, using the altona RealStar Filovirus Screen real-time RT-PCR as the bench mark assay. The performance of the Public Health England (PHE) in-house Zaire ebolavirus-specific real time RT-PCR Trombley assay was concurrently assessed. Statistical analysis using generalized estimating equations was conducted to compare LFI performance. FINDINGS: Sensitivity and specificity varied between the LFIs, with specificity found to be significantly higher for whole EDTA blood samples compared to plasma samples in at least 2 LFIs (P≤0.003). Using the altona RT-PCR assay as the bench mark, sensitivities on plasma samples ranged from 79.53% (101/127, 95% CI: 71.46-86.17%) for the DEDIATEST EBOLA (SD Biosensor) to 98.43% (125/127, 95% CI: 94.43-99.81%) for the One step Ebola test (Intec). Specificities ranged from 80.20% (158/197, 95% CI: 74.07-88.60%) for plasma samples using the ReEBOV Antigen test Kit (Corgenix) to 100.00% (98/98, 95% CI: 96.31-100.00%) for whole blood samples using the DEDIATEST EBOLA (SD Biosensor) and SD Ebola Zaire Ag (SD Biosensor). Results also showed the Trombley RT-PCR assay had a lower limit of detection than the altona assay, with some LFIs having higher sensitivity than the altona assay when the Trombley assay was the bench mark. INTERPRETATION: All of the tested EVD LFIs may be considered suitable for use in an outbreak situation (i.e. rule out testing in communities), although they had variable performance characteristics, with none possessing both high sensitivity and specificity. The non-commercial Trombley Zaire ebolavirus RT-PCR assay warrants further investigation, as it appeared more sensitive than the current gold standard, the altona Filovirus Screen RT-PCR assay.


Asunto(s)
Fiebre Hemorrágica Ebola/diagnóstico , Inmunoensayo/métodos , Adulto , Antígenos Virales/sangre , Estudios Transversales , Brotes de Enfermedades/prevención & control , Ebolavirus/genética , Epidemias , Femenino , Fiebre Hemorrágica Ebola/epidemiología , Humanos , Pruebas Inmunológicas , Masculino , Sistemas de Atención de Punto , ARN Viral/sangre , Juego de Reactivos para Diagnóstico/virología , Sensibilidad y Especificidad , Sierra Leona
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